2.1 Polyphenols and Their Relationship to Med Diet Health Benefits
23
While tasting an olive oil with an elegant green or golden yellow colour, characterized by a very intense or light complex odour and a sweet or bitter taste, you
will also find shades of freshly cut grass, apple, banana, tomato, and even artichoke.
Phenols, which are among the numerous compounds of olive oil, are most researched
by scientists and also sought after by chefs because of their peculiar flavour. Back in
1978, Montedoro and colleagues demonstrated that polyphenols impact the olive oil
flavour (Montedoro et al. 1978). The main group of phenolic compounds involved in
this process encompasses: hydroxytyrosol, tyrosol and three acids: caffeic, coumaric
and p-hydroxybenzoic acids. Based on the same study (Montedoro et al. 1978), very
relevant to the sector even nowadays, phenols may be a biomarker of olive oil quality.
The presence of hydroxytyrosol (one of the most powerful antioxidant phytochemicals) seems to be linked to good quality olive oils; on the other hand, tyrosol and
some phenolic acids, such as some derivatives of p-coumaric acid, are associated to
lower quality attributes of olive oil.
Kiritsakis has grouped phenolic compounds of Koroneiki olive fruits based on
their odour description (Kiritsakis 1998). According to the thesis of Harzallah and
as reported by Kiritsakis only, 14 phenolic compounds among 42 phenols are odourless (Harzallah 1993). However, seven of some studied phenols can influence fruity
attributes of olive oil (Kiritsakis 1998). The fruity attribute of olive oil is the basic
parameter to grade olive oil. Based on the international olive oil standard, in order
to be graded as ‘extra virgin’ or ‘virgin’, olive oil must have a fruity value of over
zero. In fact, the International Olive Council (IOC) has developed a standard for the
objective sensorial assessment of olive oil in order to determine oil’s quality and
commercial trade value. This assessment method is based on panels of selected and
trained tasters recognizing the absence and/or presence of specific positive and negative attributes. Among olive oil’s flavor notes, one may find the ‘fruity attribute’,
which is ‘set of olfactory sensations characteristic of the oil which depends on the
variety and comes from sound, fresh olives, either ripe or unripe. It is perceived
directly and/or through the back of the nose’ (IOC 2018).
Two of the three positive attributes of olive oil are the pungent and the bitter
features. Bitter is ‘characteristic primary taste of oil obtained from green olives or
olives turning colour. It is perceived in the circumvallate papillae on the ‘V ’ region of
the tongue’ (IOC 2018). Pungent positive attribute is defined by IOC in the following
way: ‘biting tactile sensation characteristic of oils produced at the start of the crop
year, primarily from olives that are still unripe. It can be perceived throughout the
whole of the mouth cavity, particularly in the throat’ (IOC 2018).
Consequently, varying intensity of bitterness and pungency can be found; oil made
from riper fruit will have little to no bitterness, while oil made from greener fruit can
be distinctly bitter. Pungency is a peppery sensation; it is a chemical irritation, like
the hotness of chilli pepper. Pungency can be mild—slight tingle—or it can be very
intense to make the consumer cough. The IOC has classified the intensity of olive
oil (OO) attributes into three categories: robust, medium and delicate (IOC 2018).
Positive attributes, mainly bitter and pungent, are linked to the presence of
polyphenols. The taste of olive oil can be intense and bitter or mellower. According to
23
While tasting an olive oil with an elegant green or golden yellow colour, characterized by a very intense or light complex odour and a sweet or bitter taste, you
will also find shades of freshly cut grass, apple, banana, tomato, and even artichoke.
Phenols, which are among the numerous compounds of olive oil, are most researched
by scientists and also sought after by chefs because of their peculiar flavour. Back in
1978, Montedoro and colleagues demonstrated that polyphenols impact the olive oil
flavour (Montedoro et al. 1978). The main group of phenolic compounds involved in
this process encompasses: hydroxytyrosol, tyrosol and three acids: caffeic, coumaric
and p-hydroxybenzoic acids. Based on the same study (Montedoro et al. 1978), very
relevant to the sector even nowadays, phenols may be a biomarker of olive oil quality.
The presence of hydroxytyrosol (one of the most powerful antioxidant phytochemicals) seems to be linked to good quality olive oils; on the other hand, tyrosol and
some phenolic acids, such as some derivatives of p-coumaric acid, are associated to
lower quality attributes of olive oil.
Kiritsakis has grouped phenolic compounds of Koroneiki olive fruits based on
their odour description (Kiritsakis 1998). According to the thesis of Harzallah and
as reported by Kiritsakis only, 14 phenolic compounds among 42 phenols are odourless (Harzallah 1993). However, seven of some studied phenols can influence fruity
attributes of olive oil (Kiritsakis 1998). The fruity attribute of olive oil is the basic
parameter to grade olive oil. Based on the international olive oil standard, in order
to be graded as ‘extra virgin’ or ‘virgin’, olive oil must have a fruity value of over
zero. In fact, the International Olive Council (IOC) has developed a standard for the
objective sensorial assessment of olive oil in order to determine oil’s quality and
commercial trade value. This assessment method is based on panels of selected and
trained tasters recognizing the absence and/or presence of specific positive and negative attributes. Among olive oil’s flavor notes, one may find the ‘fruity attribute’,
which is ‘set of olfactory sensations characteristic of the oil which depends on the
variety and comes from sound, fresh olives, either ripe or unripe. It is perceived
directly and/or through the back of the nose’ (IOC 2018).
Two of the three positive attributes of olive oil are the pungent and the bitter
features. Bitter is ‘characteristic primary taste of oil obtained from green olives or
olives turning colour. It is perceived in the circumvallate papillae on the ‘V ’ region of
the tongue’ (IOC 2018). Pungent positive attribute is defined by IOC in the following
way: ‘biting tactile sensation characteristic of oils produced at the start of the crop
year, primarily from olives that are still unripe. It can be perceived throughout the
whole of the mouth cavity, particularly in the throat’ (IOC 2018).
Consequently, varying intensity of bitterness and pungency can be found; oil made
from riper fruit will have little to no bitterness, while oil made from greener fruit can
be distinctly bitter. Pungency is a peppery sensation; it is a chemical irritation, like
the hotness of chilli pepper. Pungency can be mild—slight tingle—or it can be very
intense to make the consumer cough. The IOC has classified the intensity of olive
oil (OO) attributes into three categories: robust, medium and delicate (IOC 2018).
Positive attributes, mainly bitter and pungent, are linked to the presence of
polyphenols. The taste of olive oil can be intense and bitter or mellower. According to